Steam/gamescope stops detecting(?) game window after system sleep

[hjri]

Running on a normal IBM PC, Manjaro Linux, x86_64, Intel CPU+AMD GPU. When waking system up from sleep, trying to start any game results in endless spinner. Depending on game used game audio can be heard, too. Opening overlay shows the game visuals promptly in background. Happens both with steam games and non-steam shortcuts (i.e. Kodi)

Only way to fix this is to restart Steam (or re-login, or reboot). I'm not sure if this an issue with gamescope, steam, gamescope-session or just my PC (performance is often garbage for a while after a wakeup). Any help trying to debug it would be appreciated.